(1) Objective The Animal Core will provide the investigators with chronically instrumented pregnant and nonpregnant sheep and with non instrumented pregnant and nonpregnant animals. The specific goals of the Animal Core are: (a) to obtain time-dated pregnant animals at 75 days of gestation. These animals will be randomly assigned to receive either vehicle or betamethasone injections at 80 an 81 gays gestation, (b) to prepare chronically instrumented adult or fetal sheep for use in the different research projects, (c) to conduct necropsies and facilitate the collection of tissues for the in vitro studies described in the individual projects, (d) to facilitate the in vivo studies involving monitoring physiologic variables in fetal, pregnant and nonpregnant sheep under acute or chronic conditions.